Historically the diameter of the crossbow bolt has been of a uniform construction, based upon the crossbow stock and rails from which it is fired. If a traditional bolt is not of a specific or even uniform diameter along its length, aiming the bolt is difficult and shots may become unpredictable; two characteristics to be avoided in a sport that emphasizes repeatability and predictability in aiming and accuracy. The crossbow stock and rails often determine the minimum/maximum diameter of a bolt, which must also be uniform in order to achieve a straight bolt flight path as it leaves the crossbow string.
Small diameter crossbow bolts have been developed to provide lighter weight bolts that travel faster and provide higher kinetic energy at impact with the target while remaining simple to manufacture, even providing the ability to retrofit traditional arrows for use in a crossbow.
The small diameter crossbow bolt includes a small diameter shaft having a leading end with an insert to receive a point. The trailing end of the shaft has a nock and adjacent fletching. The shaft is a small diameter fiber reinforced plastic (FRP) arrow having an outer diameter in the range of 0.220 to 0.245 inches, with a typical rating of 8.8 grains per inch.
The insert receives a point, such as a target point, broad head, or any other point known in the industry. A circumferential spacer is positioned along the shaft midway between the insert and the nock and moved along the shaft as needed to locate the spacer for a particular weight distribution, center of gravity, to accommodate various crossbow rail designs, or to separate the spacer from the nock.
The insert, spacer, and neck each have a diameter substantially equal to the diameter of a prior art bolt. When the diameters of the nock and spacer are the same as the diameter of a prior art bolt, the small diameter crossbow bolt is positioned such that the small diameter shaft sits horizontally above the rail, and thus can be used interchangeably with prior art bolts with no modification of the crossbow.
Small diameter crossbow bolts commonly travel at velocities far in excess of prior art bolts. This often results in the bolt completely penetrating the target animal, in the case of hunting.
In light of the above, notably the significantly higher velocity and kinetic energy, it would be advantageous to provide a crossbow bolt with a second arrow head, providing the shooter with another customizable element in bolt design, allowing for improved lethality of the bolt.